The present invention relates to multiple-input multiple-output technology (MIMO) and more particularly to methods and systems for a low-complexity K-best detection.
Multiple-input multiple-output (MIMO) technology is employed in today's wireless digital communication systems to improve spectral-efficiency and robustness to fading without increasing power or bandwidth. The term MIMO refers to communication systems that use an array of antennas at both the transmitter and the receiver. In many wireless standards such as IEEE 802.16m and LTE-Advanced, MIMO may be combined with channel coding to further improve the system diversity. However, a low-complexity high-throughput VLSI implementation of near-optimum 4×4 MIMO detectors has been a major design challenge for high-order quadrature amplitude modulation (QAM) schemes. Near-optimum MIMO detectors offer scalable complexity, while providing comparable performance to the Maximum Likelihood (ML) detector. Depending on how MIMO detectors carry out the non-exhaustive search, they generally fall into two main categories: depth-first and breadth-first search. Among the breadth-first search detectors, the K-Best algorithm guarantees an SNR-independent fixed throughput with performance close to ML. Furthermore, its feed-forward detection approach makes it particularly attractive for pipelined VLSI implementation.